Objective This study aims to effectively address the issues of severe viscosity reducer channeling and low reservoir sweep efficiency during the heavy oil cold production process, and to support the green and efficient development of heavy oil.
Methods Based on the synergistic effects of efficient viscosity reduction using viscosity reducer and reservoir conformance control using dispersed particle gel in heavy oil cold production, the dispersed particle gel profile control system for heavy oil cold production was established by compounding method. The basic performance of this system was tested, and the interfacial rheological properties and shear stress characteristics were investigated by using an interfacial expansion rheometer and a rheometer.
Results The system was composed of 0.06 wt%-0.12 wt% dispersed particle gel profile and 0.05 wt%-0.15 wt% viscosity reducers. It was a uniform, low-viscosity fluid which could reduce interfacial tension and emulsifie heavy oil, and achieve a viscosity reduction rate of over 95%. The adsorption behavior of viscosity reducers at the oil-water interface determined the emulsification and viscosity reduction capacity of the system. The viscosity reducer improved coalescence stability of the system by adsorbing on the surface of the dispersed particle gel. Additionally, the study investigated the impact of component concentrations and reservoir conditions on these processes.
Conclusion A novel system was constructed which both has reservoir profile control ability and efficient viscosity reduction capability. The interaction mechanism among system components was systematically explored, which provides technical support for the chemical cold production of heavy oil.
DownLoad: